While Singapore's overall recycling rate is around 60 per cent, only 20 per cent of households do so, Environment and Water Resources Minister Vivian Balakrishnan has told Parliament.
Grace Chua The Straits Times AsiaOne 30 Apr 14;

When visitors come to Singapore, they always remark on how leafy and clean the island is. That is, until they find out how household recycling works - or doesn't.

While 61 per cent of all the rubbish chucked out last year was recycled, this was hardly the case for household waste streams such as plastic and food waste. Just 11 per cent of plastics and 13 per cent of food waste were recycled.

"Our overall recycling rate is around 60 per cent, but at the domestic (household) level, it is only around 20 per cent," said Environment and Water Resources Minister Vivian Balakrishnan in the Budget debate in February.
In 2010, British visitor Mary Veel wrote to The Straits Times Forum to express her surprise at Singapore's dismal progress in recycling.

"England is not particularly well-organised in many areas, but in the matter of recycling, we appear to have mastered more of the issues involved," she wrote.

Singapore residents, too, complain about recycling not being a social norm, and about a lack of infrastructure. "The concept of recycling is lacking in Singapore, compared to other developed countries. All one needs to do is look into any rubbish bin to find recyclables mixed with organic garbage," wrote Mr Elgar Lee last year in a letter to The Straits Times.

What exactly does recycling entail and why does it matter that Singapore is no role model in this area?

When you harvest newspapers or cardboard or cans instead of putting them into the bin, that is the first step. But after that, the materials need to be collected and processed. Newspaper gets pulped and turned into new paper; glass bottles are melted down and re-shaped into new ones.

Technologically, those steps are relatively easy. But collecting enough material to justify the cost of investing in a paper mill, or distributing the recycled paper to users, can be much harder.

Yet in a society that consumes more and more, recycling makes our environment a little bit more sustainable.

If copper and aluminium are not recycled, they have to be mined; recycling aluminium uses about 5 per cent of the energy of mining bauxite and manufacturing aluminium from it. If plastic is not recycled, it has to be made from fossil fuels, which in turn have to be extracted from the earth.

And of course, all this extraction and processing takes energy and water. As energy costs become higher and resources more scarce, the balance begins to tilt in favour of recycling.

In Singapore, there is no need to separate recyclables into metal, paper and plastic. Instead, they are separated at a centralised facility. If recyclables are put in the recycling bin properly, public waste collectors are contractually bound to collect, separate and recycle them. Usually, this means selling them to larger firms overseas that aggregate metals and sell those to metal smelters, or that collect plastics and turn them into pellets for future use.

But if the recyclables in the bin at the foot of each HDB block are contaminated with food waste or other non-recyclables, the public waste collector has to toss them out. If trash in Singapore does not get recycled, not all is lost. It gets incinerated to generate a tiny percentage, roughly 3 per cent, of Singapore's electricity.

At least, it does not get buried. In other countries, rubbish that is not recycled often goes into landfill, where plastics can take thousands of years to decompose.

Singapore does have a landfill - Pulau Semakau, south of the mainland. After rubbish is incinerated here, the ash goes to the island, along with waste that cannot be incinerated. But Singapore disposes of more than three million tonnes of rubbish a year. At this rate, Semakau will run out of space between 2035 and 2045.

So why don't we recycle more?

Many do make an effort. But there is little clarity on what can be recycled. And until 2006, no public housing block in Singapore had a recycling chute, but all had a rubbish chute, making it easier to toss everything down the chute than haul recyclables downstairs.

Things are changing, however. In 2011, the National Environment Agency started putting one bin at the foot of each block, up from one bin for every five, and new waste collection contracts from that year required public waste collectors to collect the recyclables every day. (But blocks are becoming taller, with correspondingly more recyclables and waste.)

And this year, the HDB announced it would put separate recycling chutes in all new HDB blocks, based on evidence from tests of such chutes at the Treelodge@Punggol estate. The tests found that Treelodge residents threw out far less than their neighbours - 40.4kg to 49.9kg per household a month, compared with 50.7kg to 77.2kg for other blocks in Punggol - and recycled about three times more recyclable waste than comparable housing estates without such chutes.

But in the end, some items simply do not make economic sense to recycle. For instance, the combination of plastic, foil, coffee grounds and paper in a single-serving coffee capsule is difficult to take apart.

Labour has to be very cheap in order to make some of these things economical to recycle.

For instance, it takes very cheap manual labour to painstakingly pick the tin foil apart from the plastic of a blister pack so that each can be recycled, as Adam Minter, author of Junkyard Planet, saw in India.

Moreover, it still takes energy to process old glass, melt down metal cans and shred phone books.

Most importantly, even as recycling cuts waste and saves resources, there are still two other Rs in the "reduce, re-use, recycle" triad - and these should come first even before recycling.

So to really save the planet, consumers should first use less of the stuff they do not need, and repair or re-purpose old items. When they do buy new items, they can choose from firms that have take-back programmes. For instance, telcos SingTel and StarHub have drop-off points for old phones, accessories and chargers. And they can avoid non-recyclable materials like styrofoam food boxes.

Ditching the convenience of a buy-and-throw culture for the slight inconvenience of the three Rs today is a small price for a more sustainable tomorrow.

Besides legislation, efforts being made to change habits

In Singapore, both the public and private sector have been involved in keeping the nation's waste down.

Currently, Singapore discards more than three million tonnes of garbage a year, which works out to around 8,000 tonnes a day.

This year, the Government has introduced mandatory waste-reporting for big hotels and malls.

Hotels with more than 200 rooms and malls with net rental areas of more than 50,000 sq ft (4,645 sq m) have to collect data about how much waste they generate and what their targets are for reducing and recycling it.

Typically, such moves precede a gradual broadening of legislation.

For instance, the National Environment Agency first set out mandatory energy-efficiency performance labels for some appliances, then in subsequent years, made it compulsory for those appliances.

In the past few years, the Government has also introduced physical infrastructure such as recycling chutes and more recycling bins to make it easier for residents to recycle.

On the waste minimisation front, it started the Singapore Packaging Agreement in 2007, a voluntary agreement to get packaging companies to reduce the amount of plastic and other materials they use as such waste makes up a third of domestic rubbish.

Plastic continues to make up close to a quarter of all waste disposed of in Singapore, so the agreement's effectiveness is not clear.

Meanwhile, companies and non-government organisations are working on other ways to cut waste.

In a report last year, the Singapore Environment Council pointed out that Singapore uses a staggering three billion plastic bags a year. It recommended a nationwide "bring your own bag" weekend campaign to cut the number of bags given out at supermarkets.

There are also firms engaged in the sharing economy, which involves people giving away, lending or renting items and services to maximise the efficient use of resources and reduce waste.

Renttycoons.com, for one, allows users to rent everything from bicycles to wedding decor from one another.

Ultimately, for the three Rs - reduce, reuse and recycle - to become a way of life, people's behaviour must change too. As the SEC wrote in its plastic bag report: "The common thread is that human behaviour is at the heart of each possible solution."

SINGAPORE - A sky-high government-funded project is under way to map and analyse each and every one of the thousands of rooftops here.

The aim? To figure out on average how much each is exposed to the sun.

This information will be shared with Singaporeans in the hope that more will warm towards installing solar panels, as the nation ramps up its use of the sun's energy.
This work by the Solar Energy Research Institute of Singapore (Seris) is part of an ambitious, wider effort by the Singapore Land Authority (SLA) to photograph and map, in 3D, the entire country's landscape.

Since April 10, light planes have been criss-crossing the island at an altitude of up to 1,200m, taking aerial shots and doing laser scans. The effort will take about 40 days.

The project is expected to be completed by 2016.

An SLA spokesman said that the mapping would "improve decision- making" as users such as government agencies can then visualise, analyse and understand the landscape better.

For example, national water agency PUB will be using the map to better manage storm water.

The Civil Aviation Authority of Singapore will harness it to design more efficient flight paths.

The first of the project's two phases will cost about $3.3 million.

When complete, the 3D map will be adapted for public use.

As for Seris, which is funded by the National Research Foundation, the Economic Development Board and the National University of Singapore, it aims to make its version of the map publicly available online within a year.

The Frankfurt University of Applied Sciences, which mapped the German city last year, has a similar map on its website.

Every rooftop on the Singapore map will be coloured red, orange or yellow, depending on how suited it is to harnessing solar energy.

Seris will rate this by using models to assess the slant of each roof, and simulate shadows formed as the sun rises and sets.

For example, a higher building may shade a nearby one, giving it less sun, while flat roofs are more suitable for solar panels.

Far from being just a technical exercise, the aim here is education, said Seris deputy chief executive Thomas Reindl.

A bungalow owner, condominium developer or factory owner who clicks on their rooftop would learn how much solar panel capacity they could fit on it, what this might cost, and how quickly they could recoup their investment.

It is about informing people, he said. "Solar energy has not fully taken off because people don't know too much about it yet... it has come down in price."

In October 2012, The Straits Times reported that the cost of installing and maintaining solar panels had become on a par here, for the first time, with that of using conventional electricity. Conventional electricity tariffs are 25.73 cents per kilowatt hour.

Seris is also revamping its National Solar Repository website to better educate people. Giving the public "full understanding" of solar energy's potential would help them harvest it, added Dr Reindl.

But he stressed the need to manage the impact of connecting more solar power to the national grid, an issue the Government is aware of. Solar energy generation can vary, depending on factors such as weather.

Seris will work with the Energy Market Authority to simulate the impact, using the 3D map.

Solar panels installed here as of June last year can generate at most about 12MW, six times that of 2009's figure, but a tiny fraction of the country's electricity demand.

SINGAPORE: Nanyang Technological University (NTU) aims to reduce its energy and water usage as well as carbon footprint and waste output by 35 per cent by 2020.

The move will make NTU one of the most environmentally-friendly universities in the world.

A S$20 million initiative called the EcoCampus, launched on Wednesday by Minister in the Prime Minister's Office S Iswaran, will be behind that transformation.
Under the initiative, NTU's 200-hectare campus will be used as a test bed for research projects -- from smart building systems to electric transportation.

It is a collaboration between NTU, the Singapore Economic Board and JTC Corporation.

Companies and organisations will also be involved at the projects level. 12 projects have been earmarked so far.

SINGAPORE — Companies with ideas on how to reduce energy and water usage could see them tested out at Nanyang Technological University’s (NTU) campus, which will be turned into an eco test bed as part of a S$20-million initiative by the university.

Under the EcoCampus initiative launched yesterday, NTU aims to work towards a 35 per cent reduction in its energy and water usage, carbon footprint and waste output by 2020.

To achieve this, 12 research projects have been selected by NTU so far, among them an air-conditioning management system that detects energy consumption patterns and adjusts the temperature accordingly, as well as electric buses to replace the diesel ones currently plying the campus. The projects are the result of NTU’s collaborations with 11 firms, including 3M, Siemens and Phillips.

In partnership with JTC Corporation and the Singapore Economic Development Board, NTU’s 200ha campus, together with the JTC’s 50ha CleanTech Park will be transformed into a massive test bed for companies to experiment with and commercialise sustainable urban solutions. They can range from smart building systems and renewable energy, to electric transport and water conservation technologies.

Programme director of the Energy Research Institute @ NTU (ERI@N), Mr Nilesh Jadhav, said not only would NTU be able to provide companies the space needed as a test bed for their technologies, but it can also provide them researchers to further improve their projects. “Many companies have told us that by working through this process, they will not only benefit from the common knowledge that comes from various people who joined the initiative, but also commercial opportunities,” he said.

NTU students and staff will also be actively taking part in the research projects, with possible adjustments to the undergraduate curriculum along the way. Over time, ideas that work will be implemented successively and take NTU closer to becoming one of the world’s most eco-friendly campuses. The university said its target of 35 per cent reduction was made in line with the goal set out in the Sustainable Singapore Blueprint in 2009.

At the official launch of the Eco Campus initiative yesterday, Mr S Iswaran, Second Minister for Home Affairs and Trade and Industry, said growing urbanisation has led to a greater demand for resources such as energy, water and food.

With climate change considerations and the growing demand, Mr Iswaran, who is also a Minister in the Prime Minister’s Office, said sustainability is now a strategic imperative for cities around the world.

“It offers opportunities for systems-level test bedding, which will enable us to assess innovative technologies at both the building and district levels, and establish best practices for Singapore and the tropics,” he said.

NTU is inviting companies to submit their innovative green ideas for test bedding through either the ERI@N website or the Government Electronic Business (GeBIZ) Portal. Applications can also be submitted through the EcoCampus website beginning later this month.

KOTA TINGGI: Two ships seized while anchoring illegally in the Tanjung Sedili waters here in Pengerang were found with 100 to 150 tonnes of fish.

The ships were seized and its 63 crew members were detained in separate incidents on Friday and Saturday.

Malaysian Maritime Enforcement Agency (MMEA) Tanjung Sedili enforcement division chief Captain Amran Daud said the ships' captains and crew members were detained for anchoring the ships without permission and failing to settle the light dues.
He added upon checks both ships were found with fish, believed to be in violation of the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) for Illegal, Unreported, and Unregulated (IUU) fishing.

At 10.30am on Friday, MMEA enforcement officers on routine patrol found the FV Ming 5 (FV Thunder) anchoring at three nautical miles southeast of Teluk Ramunia.

The ship was seized and its crew members were detained after the captain failed to submit the relevant permits for anchoring.

Captain Amran said FV Tai San (FV Chang Bai) was seized at 8.30pm on Saturday at 2.3 nautical miles of Teluk Ramunia.

Malaysia is among the member countries of CCAMLR.

The commission is an international effort to conserve and manage shared fish stocks that threaten the sustainability of all fisheries against IUU fishing, where areas are marked under Convention Area are opened for vessel listed, allowing them to conduct commercial fishing.

Tackling seafood fraud nationally, and cracking down on illegal fishing internationally, and protecting marine resources and their habitat and also help safeguard the health of seafood consumers, and the livelihoods of coastal communities, are among the areas where the commission governs over.

In order for vessels and ships owners to participate in fishing activities inside the Convention Area, they must be issued a licence to their flagged vessels detailing the specific areas, species and time periods that fishing is authorised.

The details of these licences must be provided to the CCAMLR's secretariat. The list of licensed vessels operating in the Convention Area is made available to all countries' enforcement agencies and also the public.

"Initial investigations revealed that one of the two ships detained, had entered the Pasir Gudang Port in Johor Baru, and loaded out their cargo of fish," Amran said.

He added that the owners may also face action under the domestic IIU regulation for fishing in Malaysian waters and using the facilities at the port, complex, and jetty without permission and permits.

A survey reveals that travellers are conscious about the environment but don’t want to pay more to protect it.

THE majority of Malaysian travellers care about the environment and are willing to pay more to protect it, a recent survey by Agoda.com revealed.

Most Malaysian holidaygoers (60.64%) indicated that they prefer eco-friendly hotels, with 42.8% willing to pay US$10 to US$50 (RM33-RM163) more to stay in one. Another 15.2% said they would be willing to fork out more than US$50 (RM163).
This puts Malaysia third in the ranks of Asian travellers who are willing to pay more to stay at an eco-friendly hotel. Brunei and Indonesia came in first and second respectively.

The online survey asked 57,000 Agoda.com customers how they felt about environmental efforts by hotels. While 58% of all travellers said they preferred hotels that claimed to be environmentally friendly, 39% said they would pay an extra US$10 (RM33) or more per night to stay in one. Seventeen percent said they’d pay up to US$5 (RM16.30) more, and 31% said they wouldn’t pay anything more.

Travellers from the Netherlands, Denmark and Britain cared the least about eco-friendly hotels. Only 35% of Danish and Dutch travellers and 38% of British travellers said they preferred them. They were among the least likely to want to shell out more cash, too, with 57%, 47% and 47% respectively saying they would not pay anything extra to stay in a green hotel.

The biggest fans of green hotels were travellers from China. An impressive 79% said they were more likely to stay in eco-friendly hotels. When it came to opening their wallets, though, they were a little less enthusiastic. Only 35% said they would pay US$5 (RM17.50) or more per night to stay in a green hotel.

When asked which environmentally-friendly hotel practices they liked the most, travellers picked use of environmentally-friendly cleaning products and recycling as their favourites, each taking about 37% of the total votes cast (respondents were allowed to select as many as they wanted from a list of eight common practices). The least popular was reusing towels and sheets, which got only 23% of the votes.

Rising sea levels caused by climate change and offshore land exploitation for building hydroelectricity plants are threatening the safety of the locals and Ba Dong Beach.

The Ba Dong Beach, located in Tra Vinh Province's Duyen Hai District, is famous for its well-preserved primitive beauty, sand dunes, tranquil sea, and fresh air.

It is a blazing hot day, but Dang Van Phuong and his entire family are engrossed in removing the furniture from their low, tin-roofed house supported by wooden columns that are buried in a sand bank.
Living in proximity to the place where flood tides had destroyed the sea dyke last year and caused a huge crack measuring 1,400 metres in length, Phuong and his kin are apprehensive about the looming dangers.

Thus, they want to move over to a new house further towards the mainland, though it is only some hundred metres away from their current home.

"My house was once at a distance from the sea, but flood tides have encroached on the sea coast, thereby displacing it nearer to the sea," Phuong said, recalling the night when flood tides inundated his neighbourhood of Con Nhan in Duyen Hai District.

"I heard the roar of the sea waves throughout the night. When I woke up, my house was already submerged in knee-deep waters," he recollected.

Flood tides inundated the entire area under watermelons that Hai intended to harvest for sale in the previous Lunar New Year.

Although Phuong has buckled down on growing new crops, the fruit can no longer be grown, as the soil has become alkaline due to the sea water.

He is no exception, as nearly 197 households in Con Nhan have suffered property losses from the flood tides.

Con Nhan means leisureliness in Vietnamese language. But, according to Phuong, people residing in the neighbourhood are always in a hurry and are toiling away all year round.

Widespread

Moreover, the flood tides are also affecting hundreds of households in Truong Long Hoa, Hiep Thanh, and Dan Thanh communes, which form the Ba Dong beach in Duyen Hai District.

According to Deputy Chairman of Truong Long Hoa Commune People's Committee Nguyen Van Uol, as many as 146 households in the three hamlets of Con Trung, Khoan Tieu and Nha Mat are being threatened by flood tides.

The commune is renowned for its sand dunes, which are naturally shaped by the sea breeze, and Nha Mat, which is a pleasure house built by the French in the early part of the 20th century.

"People in the coastal areas are living in fear, particularly 85 households in Khau Lau neighbourhood where sea dykes and forest trees were swept away by flood tides, inundating all houses and forcing the local people to relocate to higher places. Though the people have returned to their houses, they are always in a state of anxiety and uncertainty," Uol noted with a grim look.

Hundreds of households in Hiep Thanh Commune have also lost their land to flood tides. A wife of a war martyr, Truong Thi Dinh, remarked that a water nymph had taken over her house and farming land, so her family is leading a life of destitution.

"Our life is precarious because we do not have any farming land. My only child has to work as a hired labourer, even then we find it hard to feed all our grandchildren," the 74 year-old woman claimed.

According to Chairman of Hiep Thanh People's Committee Nguyen Van Kiem, flood tides have washed away about 2 kilometres of land at the deepest site and several hundreds of metres at the narrowest point. The commune has lost about 200 hectares of arable land.

Once protected by mangrove forests, Hiep Thanh and other adjoining communes were covered by alluvium. But, things started to change since 1997, when a huge storm damaged the residual mangrove forests. Adding to the natural disaster is the human destruction of forests to procure land for shrimp farming, thereby causing severe land erosion at the seashore.

By 2010, land erosion caused property losses amounting to more than VND3.7 billion (US$1.8 million). Currently, more than 500 households have been affected by sea erosion, of which 165 households need to be relocated immediately, Kiem pointed out.

Due to limitations in the state budget, the commune has been able to build just one resettlement area to accommodate 48 households that were prioritised. Specifically, each household was given a plot of land and VND10 million to build their own house.

The resettlement area has been put into use since 2011, but it is yet to have its own school and clinic. Kiem noted that a clinic is being built, and there are plans to build a kindergarten here.

Numerous difficulties still lay ahead. Kiem explained that an increasing number of households need to be relocated to resettlement areas every year. In addition to this, they also face the thorny issue of how to help the resettled households earn their livelihood in new places, he added.

Causes of flood tides

The Duyen Hai District People's Committee has recently issued a report on the impact of sand dredging, climate change, and rising sea water levels as the key reasons behind land erosion, though diverse opinions exist related to the document.

Director of Tra Vinh Irrigation and Flood Control Department Nguyen Van Truong elaborated that although it is already clear that climate change and the impact of rising sea levels have caused land erosion, more research is necessary to find whether land dredging is also the culprit because land erosion had occurred in places located miles away from sand dredging sites and before the Duyen Hai Electricity Centre was built.

Deputy Chairman of Duyen Hai District People's Committee Chau Hoang Nghia shared the same viewpoint, stressing that sand dredging will cause geographical changes in a vast region, and facts have shown that land erosion has become formidable since such projects have begun.

"Exploiting sand at the seashore will change its terrain and create a whirlpool, thereby causing landslides at the seashore and adjacent areas," reported Professor Nguyen Ngoc Tran.

Located in Dan Thanh and Truong Long Hoa communes, the Duyen Hai Electricity Centre needs more than 26 million cubic metres of sand to level the surface of its ground for the construction of three thermoelectricity plants.

To achieve this, it sought permission from local authorities to dredge sand at the seashore. It not only exploited sand in areas approved by the local government, but the centre also did it illegally, though they were not able to obtain licences to exploit sand in other places.

Having imposed administrative fines upon its illegal sand dredging for a long time, the local government decided to bar the centre from mining sand last year, as land erosion at the seashore continues to occur in the province.

Though several billions of dong have been spent on consolidating the sea dyke system each year, such investment has proven futile in the following year due to the flood tides.

Necessary measures

To mitigate the ravages inflicted by the sea, Truong believes that it is necessary to build a stone embankment to cope with the sea waves. Accordingly, the district has invested VND83 billion ($39 million) in building a 2-kilometre-long embankment to protect its land.

Yet, such investment is still too small in comparison with the province's actual needs.

"Once the projects are completed, thousands of households living at the seashore will be able to live and work in peace," he claimed.

In addition to this, Truong stressed that the mangrove forests will help to maintain the shoreline. To do so, efforts need to be taken in order to preserve alluvium for growing forests. Tra Vinh Province will grow 500 metres of mangrove forest on alluvial soil as a pilot project in the coming time, he said.

A peaceful life for the local people in Tra Vinh is still a far-fetched dream, as fund shortage remains a major hindrance to realising that dream.

Scientists from James Cook University have simulated high ocean temperatures to see if coral larvae still move freely in reef waters.

They found the larvae or coral babies are more likely to stay in the reef where they were spawned.
Professor Sean Connolly says it could mean changes to reef diversity.

"For systems of very highly connected reefs like the Great Barrier Reef where there's likely to be a lot of exchange of larvae, by weakening coral's ability to do that it puts greater pressure on things like evolutionary adaptation and so forth, which can have a lot of trouble coping with periods of rapid change," he said.

"For corals, because they're attached to the reef as adults, the only way they can migrate is through the dispersal of larvae and so the less dispersal there is, the more their capacity to change their geographic range to follow suitable temperature conditions, the more that capacity is going to be impaired."

Coral stays home when the heat's on
As the ocean gets warmer, baby coral are becoming more reluctant to leave home.9 News National 28 Apr 14;

A Queensland study has found that as ocean temperatures rise more coral larvae may remain on their birth reefs rather than exploring the underwater world and finding a new system on which to settle.

This is bad news for larger reefs like the Great Barrier Reef which rely on the recruitment of larvae from other systems but good news for smaller reefs which will retain larvae that would otherwise drift elsewhere.

Study co-author James Cook University Professor Sean Connolly says this will make it more difficult for larger systems to recover after cyclones and coral bleaching because fewer larvae will disperse from other reefs.

"The loss of connectivity can make reef systems such as the Great Barrier Reef more vulnerable," Mr Connolly, from the ARC Centre of Excellence for Coral Reef Studies (Coral CoE), said.

Although smaller reefs will have better protections by retaining their larvae, they will have fewer opportunities to change their species to adapt to climate change, he says.

Study co-author Professor Andrew Baird, also from the Coral CoE, says the research shows climate change presents both challenges and opportunities to those who manage the reef.

"The stronger link between adults and recruits means an even greater benefit if we reduce local threats such as dredging and fishing," he said.

"(However) this does not reduce the need for global action on climate change."

Increased Local Retention of Reef Coral Larvae as a Result of Ocean Warming was published in the Nature Climate Change journal.

Increasing ocean temperatures due to climate change will soon see reefs retaining and nurturing more of their own coral larvae, leaving large reef systems less interconnected and potentially more vulnerable. "We found that at higher temperatures more coral larvae will tend to stay on their birth reef," says the lead author of the study.

Researchers have found that increasing ocean temperatures due to climate change will soon see reefs retaining and nurturing more of their own coral larvae, leaving large reef systems less interconnected and potentially more vulnerable.

"We found that at higher temperatures more coral larvae will tend to stay on their birth reef," says the lead author of the study published today, Dr Joana Figueiredo from the ARC Centre of Excellence for Coral Reef Studies (Coral CoE) at James Cook University.

"This is good news in an otherwise cloudy picture for isolated reefs, because in the future they will be able to retain more of their own larvae and recover faster from severe storms or bleaching events," she adds.

Professor Sean Connolly, also from the Coral CoE, explains that while more coral larvae will stay close to their parents, fewer will disperse longer distances, leaving reefs less connected.

"The loss of connectivity can make reef systems such as the Great Barrier Reef more vulnerable," he said.

"So interconnected reef systems that depend on the recruitment of coral larvae may take more time to recover after a disturbance, such as a cyclone, because fewer larvae will disperse from other reefs to the disturbed reef."

Professor Connolly adds that weaker connections between reefs means warm-adapted corals, such as those in the northern Great Barrier Reef, may take longer to expand their ranges to the south.

Similarly for isolated reefs, Dr Saki Harii from the University of the Ryukyus says, "While isolated reefs can retain more of their own larvae, this also leaves them with fewer possibilities to change their species composition to adjust to climate change."

Professor Andrew Baird from the Coral CoE says the implications of the research present management with both challenges and opportunities.

"Our results demonstrate that global warming will change patterns of larval connectivity among reefs. On a positive note, the stronger link between adults and recruits means an even greater benefit if we reduce local threats such as dredging and fishing methods that can damage corals," Professor Baird says.

Nevertheless, he explains, "This does not reduce the need for global action on climate change."

Increased local retention of reef coral larvae as a result of ocean warming by Joana Figueiredo, Andrew H. Baird, Saki Harii and Sean R. Connolly appears in Nature Climate Change.

Subsiding land is a bigger immediate problem for the world's coastal cities than sea level rise, say scientists.

In some parts of the globe, the ground is going down 10 times faster than the water is rising, with the causes very often being driven by human activity.

Decades of ground water extraction saw Tokyo descend two metres before the practice was stopped.
Speaking at the European Geosciences Union General Assembly, researchers said other cities must following suit.

Gilles Erkens from the Deltares Research Institute, in Utrecht, in the Netherlands, said parts of Jakarta, Ho Chi Minh City, Bangkok and numerous other coastal urban settlements would sink below sea level unless action was taken.

His group's assessment of those cities found them to be in various stages of dealing with their problems, but also identified best practice that could be shared.

"Land subsidence and sea level rise are both happening, and they are both contributing to the same problem - larger and longer floods, and bigger inundation depth of floods," Dr Erkens told BBC News.

"The most rigorous solution and the best one is to stop pumping groundwater for drinking water, but then of course you need a new source of drinking water for these cities. But Tokyo did that and subsidence more or less stopped, and in Venice, too, they have done that."

The famous City of Water in north-east Italy experienced major subsidence in the last century due to the constant extraction of water from below ground.

When that was halted, subsequent studies in the 2000s suggested the major decline had been arrested.

Pietro Teatini's research indicates that significant instances of descent were now restricted to particular locations, and practices: "When some people restore their buildings, for example, they load them, and they can go down significantly by up to 5mm in a year." How far they descended would depend on the type and compaction of soils underneath those buildings, the University of Padova researcher added.

Like all cities, Venice has to deal with natural subsidence as well.

Large-scale geological processes are pushing the ground on which the city sits down and under Italy's Apennine Mountains. This of itself probably accounts for a subsidence of about 1mm each year. But on the whole, human-driven change has a greater magnitude than natural subsidence.

Scientists now have a very powerful tool to assess these issues. It is called Interferometric Synthetic Aperture Radar. By overlaying repeat satellite images of a specific location, it is possible to discern millimetric deformation of the ground.

Archives of this imagery extend back into the 1990s, allowing long time-series of change to be assessed.

The European Space Agency has just launched the Sentinel-1a radar satellite, which is expected to be a boon to this type of study.